SW2: Terminal interface

Interface with HSD terminal.

OFF: RS-449 (D-SUB 37 pin connector).

ON: RS-232 (D-SUB 25 pin connector).

SW3: Automatic data rate switching

Determines whether to receive data at data rate other than what is set with the Data Rate switch in the switch panel.

OFF: Prevents reception of data received at data rate other than which is set with the data rate switch.

ON: Enables reception of data received at data rate other than which is set with the data rate switch.

SW4: Command format

Sets command format to the HSD modem, and is only effective when SW1 is set for address call (ON). Set according to specification of HSD terminal.

OFF: HDLC format

ON: BSC format

HDLC command format

Flag

Addr

Control

Command/Indication

FCS

Flag

Flag: Flag

b0 b1 · · · · ·

b7

 

 

 

Address: Address Field

0

1 1 1 1 1 1

0

 

 

 

Control: Control Field

1

1 1 1 1 1 1

1

 

 

 

FCS: Frame Check Sequence

1

1 0 0 1 0 0

0

 

 

 

Parity added only to command, indication. (b0) sent first along signal wire.

BSC command format

SYN

SYN

SYN

STX

Command, Indication

ETX

SYN: 16H

Three SYN sent from HSD terminal to

STX: 02H

HSD modem. However, only two SYN are

ETX: 03H

necessary between the HSD modem and

 

the HSD terminal.

Parity is also added to these control characters. LSB is first sent along the signal line.

SW5: Character format

Sets character format to the HSD modem, and is only effective when SW1 is set for ad- dress call (ON). Set according to specification of HSD terminal.

OFF: 8 bit, no parity

ON: 7 bit, even, odd parity

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Furuno IB-681 manual SW2 Terminal interface